[theducks]

Not quite sure what is going on in this case, but here is a tip to make the book-series manage thing easier

Manage Series Plugin (this also uses the exact same name for all in the group. no stray characters)

Places to look while Troubleshooting ;

Tag Browser: Series. Do you see multiple entries? You can rename an entry right there: Rightclick menu: Rename
or Manage Series . But unlike Manage Authors, you can not manipulate the series_sort data from this

Tweaks: did you ever change the

# Control sorting of titles and series in the library display
title_series_sorting = 'library_order'

? That will change how article sortin was handled at entry time.

Ninjad by Kovid